Yes you can use but u need to add more DEX to meet the requirements for ORB (basically you use the stats for Force Blader). The bad thing is you have to get the DEX from somewhere and that is usually from STR. FS is a STR build. You lose more defense, attack, and damage reduction but you gain more attack and def rate. Before it was really no big deal because you can still get some attack and def from DEX but not anymore after the last two updates.